Compilare: user.cpp: In function ‘int main()’: user.cpp:7:11: warning: unused variable ‘fin’ [-Wunused-variable] FILE *fin = freopen("adunare.in", "r", stdin); ^ user.cpp:8:11: warning: unused variable ‘fout’ [-Wunused-variable] FILE *fout = freopen("adunare.out", "w", stdout); ^ user.cpp:10:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&a,&b); ^